1. Field of the Invention
The invention relates to a method for utilizing vaporizable liquid fuels, residues and waste by gasification to recover in post gasification processing, useful products from a gasified form of the fuels residues and wastes, as well as apparatus for carrying out the method for the gasification of fuels, residues and waste which are completely vaporized before being fed to the gasification process.
By fuels, residues and waste are meant, herein as including, hydrocarbons such as gasolines and fuel oils, halogen-containing or nitrogen-containing hydrocarbons from industry or contaminated solvents or mixtures.
2. Description of the Related Art
It is known, and is the state of the art, in the gasification of liquid fuels, residues and waste in a free-flowing stream, to feed these in the liquid state to the gasification reactor via a burner and to divide them into fine droplets by pressure atomization or by an atomizing medium. (Kohlenvergasung, Brennstoffwirtschaft International [Coal Gasification, Fuel Economy International], number 4, Verlag Glückauf GmbH, Essen 1979). The flame geometry, the carbon conversion degree and the conversion rate are determined critically by the drop size. At the same time, the gasification conditions are selected, with reference to the gasification temperatures, the gasification pressure and the composition of the gasifying medium, namely industrial oxygen and water vapor, in such a way that the formation of soot is ruled out thermodynamically. It is shown in practice, however, that 1 to 4% of the carbon contained in the gasification material occurs, ungasified, in the form of soot and has to be removed from the crude gas in the purification processes which follow gasification. This toxic soot is treated at considerable outlay and is returned for gasification. In the reclamation of useful materials, for example of halogen hydracids in the gasification of halogen-containing residues and waste, the soot which occurs is detrimental to the quality of this useful material and requires additional technological measures for purification.
U.S. Pat. No. 4,950,309 discloses a method for utilizing fuels, residues and waste by gasification in the free flow with a gasifying medium containing free oxygen, in which the gasification materials mentioned, in contrast to the proposed method, are not present as a homogeneous liquid phase but rather as a slurry in the form of a heterogeneous solid-liquid two-phase system. By way of the prior heating the liquid portions are completely or partially vaporized and fed as a steam-solid mixture to the gasification reactor. The purpose of the partial or complete vaporization of the liquid portions is primarily to feed the solids already in the dry state to the gasification reactor in order not to impede the gasification process with an upstream drying process. With that however only a process with which a heterogeneous gas-solid two-phase system is produced, is disclosed.